Problem: Daniel is 5 times as old as Michael and is also 20 years older than Michael. How old is Michael?
Solution: We can use the given information to write down two equations that describe the ages of Daniel and Michael. Let Daniel's current age be $d$ and Michael's current age be $m$ $d = 5m$ $d = m + 20$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $m$ , and both of our equations have $d$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $5m$ $-$ $ (m + 20)$ which combines the information about $m$ from both of our original equations. Solving for $m$ , we get: $4 m = 20$ $m = 5$.